约翰霍普金斯大学Kishore Kuchibhotla小组近日取得一项新成果。经过不懈努力，他们报道了感觉皮层中潜在知识的迅速涌现推动着学习。这一研究成果发表在2025年3月19日出版的国际学术期刊《自然》上。

在这里，该课题组研究人员研究了学习和感觉皮层表征之间的关系。研究组对小鼠进行了听觉上的“走”/“不走”任务训练，将任务附带事件的快速获取（学习）与其较慢的表达（表现）分离。光遗传沉默表明，听觉皮层既能促进快速学习，也能促进较慢的表现，但一旦小鼠达到“专家”表现，听觉皮层就变得可有可无。在整个学习过程中，听觉皮层神经元的双光子钙成像并没有增强线索表征，而是揭示了两种高阶信号，这些信号对学习和表现有促进作用。奖励预测信号在几十次试验中迅速出现，在训练早期的行动相关错误后出现，在专家型小鼠中消失。在这个信号出现时沉默会损害快速学习，这表明它起着联想作用。一个独特的细胞集合编码和控制舔抑制，驱动较慢的性能改进。这些集合在空间上是聚在一起的，但与感觉表征不耦合，表明听觉皮层内的高阶功能分离。他们的研究结果表明，感觉皮层表现出更高阶的计算能力，这些计算能力分别驱动快速学习和较慢的性能提高，从而重塑了他们对感觉皮层基本作用的理解。

据介绍，在生态环境中，快速学习赋予动物显著的优势。尽管需要速度，但动物似乎只能缓慢地学会将奖励行为与预测性线索联系起来。这种缓慢的学习被认为是由感觉皮层中线索表征的逐渐变化所支持的。然而，越来越多的证据表明，动物的学习速度比传统的表现测量方法所显示的要快，这对感觉皮层可塑性的主流模型提出了挑战。

附：英文原文

Title: Rapid emergence of latent knowledge in the sensory cortex drives learning

Author: Drieu, Cline, Zhu, Ziyi, Wang, Ziyun, Fuller, Kylie, Wang, Aaron, Elnozahy, Sarah, Kuchibhotla, Kishore

Issue&Volume: 2025-03-19

Abstract: Rapid learning confers significant advantages on animals in ecological environments. Despite the need for speed, animals appear to only slowly learn to associate rewarded actions with predictive cues1,2,3,4. This slow learning is thought to be supported by gradual changes to cue representation in the sensory cortex2,5. However, evidence is growing that animals learn more rapidly than classical performance measures suggest6,7, challenging the prevailing model of sensory cortical plasticity. Here we investigated the relationship between learning and sensory cortical representations. We trained mice on an auditory go/no-go task that dissociated the rapid acquisition of task contingencies (learning) from its slower expression (performance)7. Optogenetic silencing demonstrated that the auditory cortex drives both rapid learning and slower performance gains but becomes dispensable once mice achieve ‘expert’ performance. Instead of enhanced cue representations8, two-photon calcium imaging of auditory cortical neurons throughout learning revealed two higher-order signals that were causal to learning and performance. A reward-prediction signal emerged rapidly within tens of trials, was present after action-related errors early in training, and faded in expert mice. Silencing at the time of this signal impaired rapid learning, suggesting that it serves an associative role. A distinct cell ensemble encoded and controlled licking suppression that drove slower performance improvements. These ensembles were spatially clustered but uncoupled from sensory representations, indicating higher-order functional segregation within auditory cortex. Our results reveal that the sensory cortex manifests higher-order computations that separably drive rapid learning and slower performance improvements, reshaping our understanding of the fundamental role of the sensory cortex.

DOI: 10.1038/s41586-025-08730-8

Source: https://www.nature.com/articles/s41586-025-08730-8